In general, a fuel vapor treatment apparatus includes a canister that accommodates an adsorbent such as activated charcoal for adsorbing fuel vapor. Atmospheric air is introduced into the canister by a pump, which is driven using a motor, so that atmospheric air passes through the adsorbent. Fuel vapor adsorbed by the adsorbent in the canister is desorbed by suction pressure generated by intake air flow. The motor generates heat as the motor drives the pump. According to JP-A-2002-155812, a motor is-mounted in an adsorbent, so that heat generated from the motor is utilized for enhancing desorption of fuel vapor from the adsorbent.
However, in this structure, the pump driven by the motor is exposed to the outside the casing of the canister. In addition, the pump is fixed to the casing of the canister, which accommodates the adsorbent. Therefore, sound and vibration may be transmitted from the pump to the outside directly or via the canister. Consequently, sound and vibration caused in the operation of the motor and the pump may increase.